(1) Field of the Invention
The present invention relates to a method for bonding together ends of a sealing strip such as the ends of a split gasket and an apparatus for carrying out the method.
(2) Description of the Prior Art
Sealing strips have been used in a variety of different applications to keep solid materials such as dust and liquid materials such as water from entering a particular environment. For example, sealing strips have been used on windows, doors, covers, and the like for maintaining a tight joint between two edges or faces which can be parted in the plane of, or at right angles to the joint. These sealing strips have taken a variety of different shapes and configurations.
U.S. Pat. No. 3,029,481 to Henniges illustrates one such sealing strip formed from an elastic compound. This sealing strip has utility in a number of different applications, some of which require the sealing strip to maintain a certain rigidity. In order to enable the sealing strip to exhibit the necessary rigidity, Henniges' sealing strip is provided with a slot for receiving a metal strip.
U.S. Pat. No. 4,064,924 to Catlett illustrates a generally U-shaped sealing strip applied to edges of a panel located along the center line of a doorway. The sealing strip includes a flexible web or hinge section and a pair of substantially rigid arms that extend outwardly from the end section. The inner surface of each arm is provided with a series of teeth which engage opposite faces of the panel on which the sealing strip is mounted. The teeth are locked in engagement with the faces of the panel by a locking unit which includes a female locking element and a cooperating male element both of which have cooperating ratchet type teeth. Engagement of the ratchet teeth prevents the arms from being spread apart and thereby maintains tight engagement of the sealing strip to the edge of the panel.
A similarly constructed edge seal for an exterior door such as a storm door is illustrated in U.S. Pat. No. 5,168,669 to Knapp. As shown therein, an adjustable lower edge seal assembly for an exterior door comprises an elongated sealing strip member having a seal carrying base and a transverse edge attachment flange which is secured to an outer face of a door adjacent the lower edge thereof. A flexible seal projects outwardly of the base. The flange is provided with holes to receive fasteners to secure it to the lower edge wall of the door. The base is also provided with an adjustable connector to receive a connecting flange of a stabilizing connector strip member therein. The stabilizing connector strip member has an abutment wall to abut an opposed face of the door adjacent an opposed lower edge of the door. The stabilizing connector strip also has a transverse rear retention wall defining teeth of saw-tooth cross-section. The teeth engage similarly constructed teeth in a connector portion of the seal assembly.
U.S. Pat. No. 5,054,240 to Nakahara et al. illustrates a weather strip used in vehicles. The weather strip has an end member for sealing an open end thereof. The end member includes a fastening portion for elastically holding a portion of the edge of the vehicle which is covered by the weatherstrip to retain the end member to the open end of the weatherstrip and a sealing portion for blocking the open end of the weatherstrip. The various embodiments of the end member include a number of different male and female connections for joining the end member to the weatherstrip.
Sealing strips taking the form of gaskets are used in a number of application. One such use is in submarine torpedo tubes. Currently, existing submarine torpedo tube slide valve gaskets are made in one piece. When they start to leak, a considerable amount of effort is required to replace them. Efforts have been made to determine the feasibility of utilizing a strip of gasket material which is bonded end to end to simplify the gasket replacement procedure. In addition to simplifying the existing gasket replacement procedure, the use of a strip of gasket material would permit the development of different slide valve designs which up to now have been rejected due to the gasket replacement problem.
Some of the efforts in identifying the feasibility of a gasket approach have included an investigation into particular types of bonding adhesives which can be used to join the two ends of a gasket strip together. These investigations have shown that suitable bonding adhesives exist; however, two problems still must be resolved. The first problem is the difficulty involved in properly aligning the two ends of the gasket during the bonding operation. The second problem is the fact that the bonding adhesive does not have a life expectancy which is as long as the basic gasket material. Once the adhesive fails, the gasket ends may separate from one another and open up a path for leakage. Consequently, there still remains a need for a technique for securely fastening two ends of a split gasket material together.